In: Statistics and Probability
A social scientist would like to analyze the relationship between educational attainment (in years of higher education) and annual salary (in $1,000s). He collects data on 20 individuals. A portion of the data is as follows: Salary Education 43 7 54 4 ⋮ ⋮ 28 0 Click here for the Excel Data File a. Find the sample regression equation for the model: Salary = β0 + β1Education + ε. (Round answers to 2 decimal places.) Salaryˆ= Salary ^ = + Education b. Interpret the coefficient for Education. As Education increases by 1 unit, an individual’s annual salary is predicted to decrease by $8,590. As Education increases by 1 unit, an individual’s annual salary is predicted to increase by $6,890. As Education increases by 1 unit, an individual’s annual salary is predicted to decrease by $6,890. As Education increases by 1 unit, an individual’s annual salary is predicted to increase by $8,590. c. What is the predicted salary for an individual who completed 6 years of higher education? (Round coefficient estimates to at least 4 decimal places and final answer to the nearest whole number.) Salaryˆ Salary ^ $
| Salary | Education |
| 43 | 7 |
| 54 | 4 |
| 77 | 4 |
| 53 | 2 |
| 67 | 5 |
| 53 | 6 |
| 114 | 8 |
| 48 | 0 |
| 29 | 5 |
| 50 | 1 |
| 91 | 9 |
| 52 | 3 |
| 59 | 2 |
| 55 | 5 |
| 149 | 10 |
| 51 | 0 |
| 80 | 9 |
| 73 | 8 |
| 135 | 8 |
| 28 | 0 |
| Education X | Salary Y | X * Y |
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|
| 7 | 43 | 301 | 49 | 1849 | |
| 4 | 54 | 216 | 16 | 2916 | |
| 4 | 77 | 308 | 16 | 5929 | |
| 2 | 53 | 106 | 4 | 2809 | |
| 5 | 67 | 335 | 25 | 4489 | |
| 6 | 53 | 318 | 36 | 2809 | |
| 8 | 114 | 912 | 64 | 12996 | |
| 0 | 48 | 0 | 0 | 2304 | |
| 5 | 29 | 145 | 25 | 841 | |
| 1 | 50 | 50 | 1 | 2500 | |
| 9 | 91 | 819 | 81 | 8281 | |
| 3 | 52 | 156 | 9 | 2704 | |
| 2 | 59 | 118 | 4 | 3481 | |
| 5 | 55 | 275 | 25 | 3025 | |
| 10 | 149 | 1490 | 100 | 22201 | |
| 0 | 51 | 0 | 0 | 2601 | |
| 9 | 80 | 720 | 81 | 6400 | |
| 8 | 73 | 584 | 64 | 5329 | |
| 8 | 135 | 1080 | 64 | 18225 | |
| 0 | 28 | 0 | 0 | 784 | |
| Total | 96 | 1361 | 7933 | 664 | 112473 |
Equation of regression line is
b = 6.89
a =( 1361 - ( 6.8907 * 96 ) ) / 20
a = 34.97
Equation of regression line becomes
As Education increases by 1 unit, an individual’s annual salary is predicted to increase by $6,890.
When X = 6
= 34.974 +
6.891 X
= 34.974 +
6.891 * 6
=
76.32